The present invention relates to a process and system for processing fruit juice and to a juice deacidification process and system utilizing ion exchange resin columns that minimizes the amount of juice lost during the xe2x80x9csweeten-on/sweeten-offxe2x80x9d ion exchange steps.
Juice products are highly popular with consumers due to both their taste and their nutritional value. However, some fruit juices, such as those from citrus fruits, can have a level of acidity that makes them disagreeable to persons with sensitive stomachs.
Numerous individuals have been known to experience negative effects upon ingesting different foods. A true food allergy occurs when the immune system of the individual overreacts to certain proteins in food. It is believed that hundreds of food ingredients can provoke an allergic reaction. Typical foods in this regard are nuts, peanuts, milk, eggs, fish, shellfish, soybeans and wheat. Foods such as these can lead to symptoms including nausea, hives, skin rash, nasal congestion, wheezing, and the like. However, most unpleasant reactions to food are caused not by allergies but by intolerances, which tend to be less severe than true food allergies. Typical in this regard are lactose intolerance, sulfite intolerance and intolerance to monosodium glutamate, red wine, chocolate and food coloring agents. Another intolerance of some frequency is manifested by gastral distress and/or digestive difficulties which certain individuals experience shortly after ingesting orange juice products.
In some circles, it is generally assumed that the relatively high acidity of orange juice products is a primary contributor to these negative or unpleasant experiences with orange juice products for a small percentage of the population. For example, Kligerman et al U.S. Pat. No. 5,665,415 and U.S. Pat. No. 5,869,119, incorporated hereinto by reference, suggest that acidic foods or beverages such as coffee and other beverages can be combined with calcium glycerophosphate so as to raise the pH of the food or beverage by at least 0.5 pH units, such as to a pH of greater than 5.4, which typically is pH higher than desirable for superior tasting orange juice. This pH adjustment is said to reduce the tendency of the food or beverage to cause heartburn and other esophageal and/or gastrointestinal distress. This approach generally follows the conventional wisdom that ingesting antacids treats heartburn by helping to neutralize stomach acid. This approach suggests, in general, raising the pH of the food or beverage to well above 5.
Processes for deacidifying citrus juice have been known since the 1960s, and commercially-viable deacidification processes using anionic ion exchange for acid reduction of citrus fruit juices were known by 1980. However, such processing was used for deacidifying juice made from concentrate, which has a standard of identity (SOI) that permits a great range of flexibility in the processing steps with respect to the dilution and blending of the juice product.
Since that time, xe2x80x9cnot from concentratexe2x80x9d or NFC juices have become very popular with consumers because of their xe2x80x9cfresh-squeezedxe2x80x9d taste. These NFC juices must meet their own SOI criteria. Among these criteria is the avoidance of a final juice product which has water added characteristics. Other criteria typically include brix minimums and brix-to-acid ratio minimums.
For example the US Food and Drug Administration sets a standard for juices such as orange juice, including brix minimums. In this regard 21 CFR Section 146.140, incorporated by reference hereinto, states that finished pasteurized orange juice is to contain not less than 10.5 percent by weight of orange juice soluble solids, exclusive of the solids of any added sweetening ingredients. This FDA regulation further states that the ratio of brix to grams of citric acid per 100 ml of juice is not less than 10 to 1. The juice industry recognizes these criteria for pasteurized orange juice or single strength orange juice as applying to NFC orange juice. It will be understood that these SOI criteria are used herein with respect to NFC orange juice or pasteurized single strength orange juice. This same concept of SOI criteria applies as well to other pasteurized single strength juices.
While it is anticipated that there would be a significant market for a low acid NFC orange juice, deacidification processes utilizing ion-exchange resin columns can easily result in the processed juice being diluted. This is particularly true if the ion-exchange column is designed to operate with a water/juice interface or a xe2x80x9cwater domexe2x80x9d in the head space of the column above the resin bed. Such water dilution of the processed juice is unacceptable for NFC juices because the standard of identity (xe2x80x9cSOIxe2x80x9d) of the juice is compromised.
Accordingly, it is an object of the present invention to provide a process and system for deacidifying NFC juices that do not compromise the standard of identity required for such juice products.
More particularly, it is an object of the present invention to provide a process and system for deacidifying NFC juices that do not dilute the NFC juice so that NFC SOI can be maintained.
It is a still further object to deacidify NFC juices while minimizing the amount of juice that is wasted or becomes otherwise unuseable due to the deacidification process.
A further object of the invention is to provide an improved single strength juice which meets SOI criteria throughout all phases of single strength juice product collection.
These objects, as well as others that will become apparent upon reference to the following detailed description and accompanying drawings, are accomplished by a process for deacidifying single strength juice, preferably not from concentrate (NFC) juice that uses an ion-exchange column having a lower volume portion that is filled with acid-absorbing resin beads and an upper volume portion within which the resin beads are not present. The lower volume portion has an exit port, while at least one inlet port opens into the upper volume portion.
The process includes filling the resin column with water and then draining a fraction of the water from the column through the exit port to create a head space in the column above the resin beads. Untreated juice is then introduced into the resin column. In a preferred arrangement, such initial flow is through an inlet port so as to minimize resin bed disturbance. With this arrangement, after the head space has an adequate volume of juice, untreated juice can be introduced into the resin column. In the illustrated embodiment, this is through an inlet port which is at an upper location of the upper volume portion. Water is drained through the exit port until the outflowing treated liquid meets SOI criteria for the single strength juice. Untreated juice continues to be introduced, and treated juice is collected as deacidified single strength juice until a predetermined value is attained, such as when a target processing volume is obtained or until the resin is exhausted.
Treated juice is removed from the resin column to then create a head space in the column. In one approach, this leaves the resin beads wetted or even submerged. Alternatively, all free juice may be displaced out of the resin bed before the next phase introduces water into the resin bed. Water is then introduced into the head space in the column, and liquid passes through the exit port until the outflowing liquid does not meet SOI criteria for the single strength juice, at which time this liquid is no longer directed to production.